Avulsion fracture of the supinator crest of the proximal ulna in the context of elbow joint injuries.

Purpose: While performing CT examinations of the elbow, we frequently observed a previously undescribed fracture fragment of the supinator crest of the ulna. According to the anatomy of the lateral collateral ligament complex, this fracture might be an avulsion fracture of the annular ligament and/or the lateral ulnar collateral ligament. The aim of this study was to further characterize these fragments and document their associated injuries.